Tesla fans Saturday night got a first peek at something close to a final version of the full-sized Model S sedan the company plans to start delivering next year. The electric car company invited customers who had reserved one of its new Model S's to visit its factory in Fremont, the former NUMMI facility. There the Palo Alto-headquartered company offered factory tours, demonstrations of how the car will be assembled -- and a test ride in what Tesla is calling a "beta" version of the car.